Electrical snap-switch.



Patented Nov. 26, 190i.

' G. B. THOMAS.

ELECTRICAL SNAP SWITCH.

(Application filed Sept. 3, 1901.)

(No Model.)

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. rV w B WITNESSES: 4.3;?

NITED STATES P TENT FFICE.

GEORGE E. THOMAS OF HARTFORD, CONNECTICUT, ASSIGNOR TO THE PERKINS ELECTRIC SWITCH MANUFACTURING COMPANY, OF HART- FORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

ELECTRICAL SNAP-SWITCH.

SPECIFICATION forming part of Letters Patent No. 687,669, dated November 26, 1901. Application filed $eptarnber3,1901. Serial No. 74,175. (No'mocleh) T0 at whom it may comma- Be it known that I, GEORGE E. THOMAS, a citizen of the United States of America, residing in Hartford, in the county of Hartford, State of Connecticut, have invented Improvements in Electrical Snap-Switches, of which the following is a specification.

My invention relates more particularly to that class of electric snap-switches in which a rotary or oscillating commutator is combined with fixed. contacts on the base and means for tensioning a spring to efiect a quick partial rotation of the commutator and breaking of the circuit upon release of the catch device by the same movement of the means which tensions the spring.

The main object of my invention is to construct a strong and economically-manufactured commutator of this character and such that while made for single-pole switches it is at the same time adapted for the making up of double poleor other multiple pole switches.

In the accompanying drawings, Figure 1 is a perspective View, partly in section, of my improved commutator on an enlarged scale. Fig. 2 is a vertical section, drawn to a smaller scale, of a double-pole switch fitted with a pairof my interchangeable commutator units, the inclosing cover being omitted. Fig. 3 is a sectional plan view on the line 3 3, Fig. 2; and Fig. 4: is a perspective view of a form of spring which may be employed in conjunction with my commutator units.

In the drawings I have illustrated my invention as applied to the type of rotary snapswitch which forms the subject of the Gibbs patent,No. 517,100, dated March 27, 1894, and in which there is combined with the stationary contacts of the base a rotary operatingspindle having a screw-thread on which is fitted a nut normally engaging with a lock on the base, but adapted to be released therefrom by the rotation of the spindle, a commutator which turns with the nut, but in which the nut can movelengthwise of the spindle, and a spring connected between the spindle and the nut for rotating the communected at its upper end to a projection on the spindle and atits lower end engaging in a notch in the nut E. This nut E has ratchet-teeth atits lower end normally held in engagement with ratchet-teeth on the lock F of the base by the end thrust of the spring D. The exterior of the nutE is made of polygonal section, preferably a regular polygon. In the present instance I have shown it as of square section with chamfered corners, Fig. 3. Upon this nut is freely fitted the commutator C. My invention being here shown applied to a double-pole switch, the commutator is in two parts or units 0 and C precisely alike and interchangeable, oneof the advantages of my invention being that I can build up a commutator with any suitable number of poles with the aid of these independent and interchangeable commutator units. I will now describe the construction of one of these commutator parts as a complete commutator, since one such commutator part is all that is needed for a singlepole switch.

As will be seen on reference to Fig. 1, I have shown the contacts on the commutator as consisting of pairs of clips 5 5, the corresponding knife part being on the fixed contacts of the base; but this arrangement may be reversed and the contacts on the commutator may be in the form of single knives to engage spring-clips upon the fixed base. In

the construction shown the contact-clips 5 5 are formed upon metallic rings 6 6, and the pairs of clips are preferably spaced apart by placing between the rings 6 6 another ring 7. These contact and spacing rings are held together by means of external clamping-rings 8 8 and a flanged ferrule 9, with intermediate layers 10 of mica or other suitable insulating material. In order to get the requisite strength in the clamping-rings-S without unduly increasing the thickness of the finished commutator, I prefer to form these clampingrings with recesses 11 on their exterior faces at the inner edges of the rings for the reception of the flanges of the securing-ferrule 9. The commutator-is thus a self-contained unit shaped internally to be slipped onto and fit easily over the nut E-thatis, in the present instance the opening in the ferrule is square, with chamfered corners, as shown in Fig. '1. To make a double-pole switch, two of these commutator units are slipped over the nut E, with the contact-clips of the two commutators set at right angles to each other, as shown in Fig. 3. Between the two commutators I place a spacing-spring such as a ring G, Fig. 4with spring-fingers g stamped up out of and bent up from the body of the ring. A cap-plate H, held on the spindle by a retaining-nut h, confines the commutators and spring G in place longitudinally on the spindle, but with sufficient freedom of play to allow the commutators to be self-adjusting when their spring-clips come into contact with the contact-blades B B on the base upon rotation of the commutator in the usual manner. I

I claim as my invention- 1. A commutator unit for electric switches, comprising contact rings and insulating layers about them with external clampingrings and a ferrule flanged over the inner edges of the clamping-rings.

2. A commutator unitfor electric switches, comprising two contact-rings carrying clipcontacts and insulating layers about them 1 I name to this specification in the presence of two subscribing witnesses.

with external clamping-rings and a ferrule flanged over the inneredges of the clampingrings.

3. A commutator unit for electric switches comprising two contact-rings carrying clipcontacts, an intermediate spacing-ring, and insulating layers about them with external clamping-rings and a ferrule flanged over the inner edges of the clamping-rings.

4. A commutator unit for electric switches, comprising contact rings and insulating layers about them with external clampingrings and a ferrule flanged over the inner edges of the clamping-rings, the opening in the ferrule being polygonal.

5. A commutator for electric switches com prising contact-rings and insulating layers about them with external clamping-rings re cessed on their exterior faces and a ferrule I flanged over into these recesses at the inner 6o edges of the clamping-rings, substantially as described.

6. An electrical rotary snap-switch, comprising a base with contacts, a rotary operating-spindle having a part of polygonal sec- 6 5 tion, a latching device and spring with a commutator composed of two separate and inter changeable units each having an opening to fit over said polygonal part substantially as described. 7o

7. An electrical rotary snap-switch, comprising a base with contacts, a rotary oper= ating-spindle having a part of polygonal sec= tion, a latching device and spring with a commutator composed of two separate and inter changeable parts, each having an opening to fit over said polygonal part, an intermediate spacing-ring and a cap-plate for the commutator units.

8. An electrical rotary snap-switch com 8o prising a base with contacts, a rotary operating-spindle, a latching device and spring with j a commutator composed of two separate and interchangeable units,each unit being formed j of contact-rings, insulatinglayers, clampingrings and a flanged ferrule.

In testimony whereof I have signed my GEORGE B. THOMAS.

Witnesses:

G. W. GOODRIDGE, W. B. OO'VIL. 

